.nav {
  width: 100%;
  box-sizing: border-box;
  background: #f7f7f7;
  display: flex;
  height: 40px;
  border: 1px solid #dddddd; 
  border-bottom: 0;
  }
  .nav li {
    width: 100px;
    display: flex;
    justify-content: center;
    align-items: center; }
    .nav li a {
      line-height: 40px;
      font-size: 14px;
      color: #959595; }
  .nav .activeIndex {
    background: #fff;
    border-right: 1px solid #dddddd;
    border-left: 1px solid #dddddd;}
